M
Steel backed bearings with a Micro-Babbitt lining (a very thin layer of lining which reduces the microscopic deflections that occur to a bearing when loaded and thus increases fatigue life). Solely intended for extreme high-horsepower applications.
N
Narrowed for greater crankshaft fillet clearance.
P
Steel backed bearings with an intermediate layer of copper-lead alloy and an electroplated lead-tin-copper overlay. Standard replacement material.
R
Indicates that the bearing can be resized to standard. When following a camshaft bearing, indicates that it has extra bore stock in the inside diameter.
S
Indicates a set number designation.
V
High performance bearing with a lead-indium overlay (on main sets this indicates partial groove). Solely intended for extreme high-horsepower applications.
VG
High performance bearing with a lead-indium overlay and a full annular groove. Solely intended for extreme high-horsepower applications.
X
Bearing has .001” more oil clearance than standard.
XX
Bearing has .002” more oil clearance than standard.
W
Indicates a part that is a thrust washer (may also be designated upper or lower).